<template>
	<view class="uni-numbox" :class="{ small: size == 'small' }">
		<view :class="{ 'uni-numbox--disabled': inputValue <= min || disabled, small: size == 'small' }"
			class="uni-numbox__minus" @click="_calcValue('minus')">
			-</view>
		<input :disabled="disabled" v-model="inputValue" class="uni-numbox__value" type="number" @input="_onInput"
			@blur="_onInput" :class="{ small: size == 'small' }" />
		<view :class="{ 'uni-numbox--disabled': inputValue >= max || disabled, small: size == 'small' }"
			class="uni-numbox__plus" @click="_calcValue('plus')">+</view>
	</view>
</template>
<script>
	export default {
		name: 'UniNumberBox',
		props: {
			value: {
				type: [Number, String],
				default: 0
			},
			min: {
				type: Number,
				default: 0
			},
			max: {
				type: Number,
				default: 100
			},
			step: {
				type: Number,
				default: 1
			},
			disabled: {
				type: Boolean,
				default: false
			},
			modifyFlag: {
				type: Boolean,
				default: false
			},
			size: {
				type: String,
				default: 'default'
			},
			index: {
				type: Number,
				default: -1
			}
		},
		data() {
			return {
				inputValue: 0
			};
		},
		watch: {
			value(val) {
				this.inputValue = +val;
			},
			inputValue(newVal, oldVal) {
				if (+newVal !== +oldVal && !this.modifyFlag) {
					this.$emit('change', newVal, this.index);
				}
			}
		},
		created() {
			this.inputValue = +this.value;
		},
		methods: {
			_calcValue(type) {
				if (this.disabled) {
					return;
				}
				if (this.modifyFlag) return;
				const scale = this._getDecimalScale();
				let value = this.inputValue * scale;
				let step = this.step * scale;
				if (type === 'minus') {
					value -= step;
				} else if (type === 'plus') {
					value += step;
				}
				if (value < this.min || value > this.max) {
					return;
				}
				this.inputValue = value / scale;
			},
			_getDecimalScale() {
				let scale = 1;
				// 浮点型
				if (~~this.step !== this.step) {
					scale = Math.pow(10, (this.step + '').split('.')[1].length);
				}
				return scale;
			},
			_onInput(event) {
				setTimeout(() => {
					let value = event.detail.value;
					if (!(/(^[1-9]\d*$)/.test(value))) value = this.min;
					if (!value) {
						this.inputValue = 0;
						return;
					}
					value = +value;
					if (value > this.max) {
						value = this.max;
					} else if (value < this.min) {
						value = this.min;
					}
					this.inputValue = value;
				}, 0);
			}
		}
	};
</script>
<style>
	@charset "UTF-8";

	.uni-numbox {
		display: inline-flex;
		flex-direction: row;
		justify-content: flex-start;
		height: 70rpx;
		position: relative;
	}

	.uni-numbox.small {
		height: 50rpx;
	}

	.uni-numbox:after {
		content: '';
		position: absolute;
		transform-origin: center;
		box-sizing: border-box;
		pointer-events: none;
		top: -50%;
		left: -50%;
		right: -50%;
		bottom: -50%;
		border: 1px solid #e5e5e5;
		border-radius: 12rpx;
		transform: scale(0.5);
	}

	.uni-numbox__minus,
	.uni-numbox__plus {
		margin: 0;
		background-color: #f8f8f8;
		width: 70rpx;
		font-size: 40rpx;
		height: 100%;
		line-height: 70rpx;
		text-align: center;
		display: inline-flex;
		align-items: center;
		justify-content: center;
		color: #333;
		position: relative;
	}

	.uni-numbox__value {
		position: relative;
		background-color: #fff;
		width: 80rpx;
		height: 100%;
		text-align: center;
		padding: 0;
	}

	.uni-numbox__minus.small,
	.uni-numbox__plus.small {
		width: 50rpx;
		line-height: 50rpx;
	}

	.uni-numbox__value.small {
		width: 60rpx;
		font-size: 28rpx;
	}

	.uni-numbox__value:after {
		content: '';
		position: absolute;
		transform-origin: center;
		box-sizing: border-box;
		pointer-events: none;
		top: -50%;
		left: -50%;
		right: -50%;
		bottom: -50%;
		border-style: solid;
		border-color: #e5e5e5;
		border-left-width: 1px;
		border-right-width: 1px;
		border-top-width: 0;
		border-bottom-width: 0;
		transform: scale(0.5);
	}

	.uni-numbox--disabled {
		color: silver;
	}
</style>
